Device for forming threads from natural or artificial dispersions of rubber



Oct. 20, 1936. E. A. MUR HY 2,058,032

DEVICE FOR FORMING THREADS FROM NATURAL OR ARTIFICIAL DISPERSIONS OF RUBBER Filed Dec. 23, 1931 lNI/ENTOH Patented Oct. 20, 1936 UNITED STATES DEVICE FOR FORMING THREADS FROM NATURAL OR, ARTIFICIAL DISPERSIONS OF RUBBER Edward Arthur Murphy, ErdingtomBirmingham, England, assignor to Dunlop Rubber Company Limited, Erdington, Birmingham, England, a

British corporation Application December 23, 1931, Serial No. 582,769 In Great Britain January 1,v 1931 4 Claims.

This invention is concerned with improved means of preparing threads or filaments from dispersions of substances in liquid media which tend to sediment or cream, such as those in which the dispersed materials have different densities from that of the dispersion medium.

In general it has been found that when aqueous dispersions such as rubber latex are made to flow through a length of tubing or through an orifice there is a tendency for the suspended particles to collect or pile togetherin the immediate vicinity of the wall of the tube or orifice and to cover it eventually with a layer of aqueous dispersion having a greater viscosity than that of the main bulk of the dispersion; such material of greater viscosity is hereinafter called cream. Particles of this material may become detached from time to time and accumulate in or at the orifice causing momentary partial or complete blockage of the orifice with an ensuing retardation of, or interruption in, the rate of flow with consequent distortion or discontinuity of the thread produced.

The object of this invention is to provide a thread forming device so constructed as to reduce to a minimum difficulties encountered in preparing threads or filaments from dispersions which exhibit the above characteristics.

According to this invention we provide a device for forming threads from natural or artificial dispersions of rubber consisting of an orifice in the form of a perforated membrane the bore of.

which does not exceed two millimetres in length, preferably in which the end of the orifice adjacent the aqueous dispersion lies in a substantially fiat surface the orifice being located in a membrane recessed into one of the surfaces of a dividing wall, the orifice and membrane being either integral with the wall, or formed in an independent member secured in a recesstherein.

In order that the said invention may be clearly understood and more readily carried into effect, the same will now be described more fully with reference to the enclosed drawing, in which:-

Figs. 1 and 2 are part sectional side elevations" surface 4 which may form part of a box or other container is preferably flat on the one side and in the region of the inner end of the orifice adjacent the bulk of the dispersion so as to afford no pockets liable to catch sediment which when liberated by some disturbance may stray into the path of the dispersion and impede or interrupt the stream through the orifice. I

In the alternative form shown in Fig. 2 each orifice is pierced through a cup shaped member 5 which may be of any suitable form but preferably takes the form of a truncated cone the inclined sides of which seat circumferentially in a complementary conical seating apertured in the wall I, a nice fit being obtainable by grinding the faces together. The cup member 5 may be secured to its seat in any suitable manner as for instance by the application of cement to one of the surfaces prior to their engagement, or may alternatively beefiected by the engagement of threaded portions on each member.

-The aqueous dispersions referred to comprise by way of example those including or consisting of natural or artificial aqueous dispersions of rubber, balata, gutta-percha, or similar vegetable resins, or artificial dispersions of coagulated rubber, vulcanized rubber, waste or reclaim, or mixtures of any of the aforesaid dispersions in either or both a concentrated or compounded condition, or alternatively in a condition obtained by compounding and then concentrating, the compounding ingredients comprising the usual additions such as fillers, reinforcing agents, vulcanizing agents, accelerators and softeners.'

The invention may be used in conjunction with the process and apparatus claimed in Patent No. 1,887,190, November 8, 1932, but is not limited thereto. In the process of Patent No. 1,887,190, a filament of aqueous rubber dispersion is extruded directly into a dehydrating and fixing bath.

What I claim is:

1. 'Apparatus for forming threads from aqueous dispersions of rubber which comprises a dehydrating and setting bath for aqueous dispersions of rubber, a container for'aqueous dispersion having a vertical wall to separate said dispersion from said dehydrating and setting bath,

said wall comprising a diaphragm of not over two orifice to permit particles to rise freely thereabove.

2. The apparatus of claim 1 in which said diaphragm is formed of a separate inset.

3. The apparatus of claim 1 in which said diaphragm is formed integrally with the wall.

4. A method of forming threads from aqueous dispersions of rubber which comprises separating said aqueous dispersions from a setting bath 10 on a vertical plane of separation unobstructed vertically toward said aqueous dispersion and passing said aqueous dispersion in a fine stream through said plane of separation into said setting bath and in a passage from said dispersion to said bath of not over two millimeters in length while permitting creamed dispersion to rise above said orifice and setting said stream in said setting bath as it issues from said orifice. 

